Speech recognition system

ABSTRACT

An audio operating unit of an audio apparatus is used for speech recognition. Specifically, when it is determined that a speech recognition start switch has been pressed, a speech recognition apparatus outputs a signal indicating volume down to a mute level to an audio-apparatus main body of the audio apparatus via an in-vehicle LAN. In addition, a signal indicating that speech recognition is in operation is outputted to various ECUs via the in-vehicle LAN so that speech recognition is performed. The audio-apparatus main body that has acquired the signal indicating volume down to a mute level lowers the volume to the mute level, while ignoring an output signal from the audio operating unit. On the other hand, the speech recognition apparatus executes a process related to speech recognition by, e.g., selecting or determining one of candidate words based on the output signal from the audio operating unit.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on and incorporates herein by referenceJapanese Patent Application No. 2005-251895 filed on Aug. 31, 2005.

FIELD OF THE INVENTION

The present invention relates to a speech recognition apparatus thatdetermines a syllable or word intended by a speaker based on a speechinputted thereto by the speaker.

BACKGROUND OF THE INVENTION

A speech recognition apparatus which determines, based on a speechinputted thereto by a speaker, individual monosyllables intended by thespeaker on a one-by-one basis has been widely known. In addition, aspeech recognition apparatus which receives multiple syllables as oneword has also been widely known. Such speech recognition apparatusesinclude one which displays multiple candidate speech patterns on adisplay unit when they are found as a result of the speech recognitiondescribed above such that the speaker selects a desired one of thecandidates with a speech input (see, e.g., Patent Document 1).

On the other hand, there is a speech recognition apparatus comprising anoperating unit such as a key switch for effectively narrowing downmultiple candidates as described above to a few.

-   -   Patent Document 1: JP-H8-54894 A (FIG. 2)

However, when an operating unit such as a key switch is disposed on theperiphery of a steering wheel or an instrument panel in a speechrecognition system as described above, an extra space is needed. Thiscauses the problems of, e.g., an increased number of wires and anincreased number of components.

SUMMARY OF THE INVENTION

The present invention has been achieved in view of such problems and itis an object of the present invention to provide a speech recognitionsystem with increased convenience without increasing the number ofoperating units.

According to an aspect of the present invention, a speech recognitionsystem in a vehicle is provided with the following. A speech recognitionapparatus is included for performing speech recognition. An electronicapparatus is included for performing at least a specified operation. Acommunication network is included, wherein the speech recognitionapparatus and the electronic apparatus are communicative via thecommunication network. The speech recognition apparatus includes (i) anotifying unit for transmitting, when performing speech recognition, anoperating signal indicating that the speech recognition is in operationto the electronic apparatus, (ii) a speech recognizing unit forperforming speech recognition to specify a candidate for a speechinputted by a user, (iii) a reporting unit for reporting the specifiedcandidate so as to require the user to indicate an instruction, and (iv)a first control unit for executing, when receiving an instruction signalindicating an operation performed by the user, a subsequent processbased on the received instruction signal. The electronic apparatusincludes (i) a receiving unit for receiving an operation performed bythe user and generating a corresponding instruction signal and (ii) asecond control unit. When not receiving the operating signal, the secondcontrol unit determines that the instruction signal is not related tospeech recognition and executing the specified operation based on theinstruction signal. When receiving the operating signal, the secondcontrol unit determines that the instruction signal is related to speechrecognition and transmits, without executing the specified operationbased on the instruction signal, the instruction signal to the speechrecognition apparatus. The speech recognition apparatus then executesthe subsequent process based on the instruction signal transmitted fromthe electronic apparatus.

According to another aspect of the present invention, a speechrecognition system in a vehicle is provided with the following. A speechrecognition apparatus is included for performing speech recognition. Anelectronic apparatus is included for performing at least a specifiedoperation. An operating panel is included for distributing aninstruction signal corresponding to an operation performed by a user. Acommunication network is included, wherein the speech recognitionapparatus, the operating panel, and the electronic apparatus aremutually communicative via the communication network. The speechrecognition apparatus includes: (i) a first receiving unit for receivingthe instruction signal from the operating panel; (ii) a notifying unitfor transmitting, when performing speech recognition, an operatingsignal indicating that the speech recognition is in operation to theelectronic apparatus; (iii) a speech recognizing unit for performingspeech recognition to output a candidate for a speech inputted by auser; (iv) a reporting unit for reporting the candidate so as to requirethe user to indicate an instruction; and (v) a first control unit forexecuting, when receiving an instruction signal specifying an item fromthe candidate by the instruction performed by the user via the operatingpanel, a subsequent process based on the received instruction signalfrom the operating panel. The electronic apparatus includes: (i) asecond receiving unit for receiving the instruction signal from theoperating panel performed by the user; and (ii) a second control unit.When not receiving the operating signal, the second control unitdetermines that the instruction signal is not related to speechrecognition and executing the specified operation based on theinstruction signal. When receiving the operating signal, the secondcontrol unit determines that the instruction signal is related to speechrecognition and stops executing the specified operation based on theinstruction signal. The speech recognition apparatus then executes thesubsequent process based on the instruction signal transmitted from theoperating panel.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features, and advantages of the presentinvention will become more apparent from the following detaileddescription made with reference to the accompanying drawings. In thedrawings:

FIG. 1 is a diagram of a schematic structure of a speech recognitionsystem according to a first embodiment of the present invention;

FIG. 2 is an illustrative view showing a steering wheel in which theoperating unit of an audio apparatus in the speech recognition systemaccording to the first embodiment is disposed;

FIG. 3 is a flowchart diagram for illustrating a speech recognitionprocess (1);

FIG. 4A is a view illustrating an example of the speech recognitionprocess;

FIG. 4B is a view illustrating an example of the speech recognitionprocess;

FIG. 5 is a diagram of a schematic structure of a speech recognitionsystem according to a second embodiment of the present invention;

FIG. 6 is a flowchart diagram for illustrating a speech recognitionprocess (2); and

FIG. 7 is a flowchart diagram for illustrating a mute process executedby a control unit of an audio apparatus in the speech recognition systemaccording to the second embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, the individual embodiments of the presentinvention will be described herein below.

First Embodiment

FIG. 1 is a diagram of a schematic structure of a speech recognitionsystem according to a first embodiment of the present invention. FIG. 2is an illustrative view showing a steering wheel in which the operatingunit of an audio apparatus in the speech recognition system according tothe first embodiment is disposed.

-Structure of Speech Recognition System 1-

As shown in FIG. 1, a speech recognition system 1, which is mounted on asubject vehicle, includes a speech recognition apparatus 10, an audioapparatus 20, and a display unit 40 for displaying various informationitems. The audio apparatus 20 is an electronic apparatus comprised of anaudio operating unit (or audio operating panel) 21 and anaudio-apparatus main body 22. The audio operating unit 21 and theaudio-apparatus main body 22 are constructed as separate individualparts. The speech recognition apparatus 10, the audio operating unit 21,the audio-apparatus main body 22, and the display unit 40 are connectedto be mutually communicative via an in-vehicle LAN (Local Area Network).

In the present embodiment, the audio apparatus 20 is allowed not to usea signal received from the audio operating unit 21 for performing aspecified operation when the speech recognition apparatus is performingspeech recognition. Further, the audio apparatus 20 has a function notto disturb the operation of the speech recognition when the speechrecognition apparatus 10 is performing speech recognition. In otherwords, in the audio apparatus 20, a function of the specified operation,which may disturb the operation of the speech recognition, becomesinvalidated during the speech recognition. Therefore, the presentembodiment uses the audio operating unit 21 of the audio apparatus 20for speech recognition in the speech recognition system 1.

To the in-vehicle LAN mentioned above, an onboard navigation apparatus50 and various ECUs (Electronic Control Units) not shown are connected.Since the respective structures of the onboard navigation apparatus 50and the various ECUs are compliant with known technologies, the detaileddescription thereof will be omitted herein.

-Description of Structure of Speech Recognition Apparatus 10-

The speech recognition apparatus 10 comprises: an I/F 12 for performingcommunication with the in-vehicle LAN; a speaker 13 for outputtingvarious guide speeches and the like; an A/D converter 14 for convertinga speech inputted from a microphone 16 to a digital signal; a memorydevice 15 for inputting and outputting data related to speechrecognition to and from a HDD (Hard Disk Drive) 17; and a control unit11 for controlling each of the components described above. To the A/D(Analog/Digital) converter 14, the microphone 16 for receiving a speechinput and outputting speech information is connected.

The I/F (Interface) 12 functions as means for communicating with anoutside to be connected to the in-vehicle LAN and capable ofcommunicating with the various ECUs connected to the in-vehicle LAN. Asan example of the in-vehicle LAN, a CAN (Control Area Network) can beassumed. As one of the various ECUs, an engine ECU, an AT-ECU, or a bodyECU can be assumed.

The memory device 15 is a device for inputting and outputting thevarious data items stored in the HDD 17 as a medium for storing datarelated to speech recognition. The HDD 17 stores (i) characteristicparameters for recognizing syllables, (ii) a dictionary composed ofspecified words, which are for monosyllabic recognition and each ofwhich is comprised of multiple syllables associated on a permonosyllable basis, (iii) a dictionary composed of words each comprisedof multiple syllables associated on a per monosyllable basis, and (iv)the like.

The control unit 11 is constituted by a well-known microcomputer as amain constituent, which is composed of a CPU, a ROM, a RAM, an I/O, andbus lines providing connections between these components. The controlunit 11 executes various processes based on programs stored in the ROMand the RAM. The control unit 11 can also function as means forexecuting a speech recognition process, which will be described later.

The control unit 11 also has the function of executing the followingprocess. That is, the control unit 11 determines that speech recognitionis being performed (or in operation) as long as a sequence of speechrecognition process steps are performed; it then notifies theaudio-apparatus main body 22 that the speech recognition is in operationvia the I/F 12. The speech recognition is started when the speechrecognition apparatus 10 starts to operate in response to an operationby a user and continues over a period including the period, during whicha speech uttered by the speaker is inputted to the A/D converter 14 viathe microphone 16. The control unit 11 executes a reporting process toreport candidates of syllables or words, each of which includes multiplesyllables, specified by itself to the display unit 40. The control unit11 regards a signal received via the I/F 12 from the audio operatingunit 21 as a signal indicating that one of the candidates is selected ordetermined by the speaker. The control unit 11 then determines thecandidate indicated by the signal as the speech intended by the speaker.

-Description of Structures of Audio Operating Unit 21, Audio-EquipmentMain Body 22, and Display Unit 40-

The audio operating unit 21 is comprised of mechanical key switchesprovided in a steering wheel 60 and the like (see FIG. 2). Specifically,the audio operating unit 21 outputs a signal indicating an increase or adecrease in volume via the in-vehicle LAN to the various ECUs based onan operation by the user. For easy operation of the audio operating unit21 by a driver even during driving, the present embodiment disposes theaudio operating unit 21 in the steering wheel 60 which is located withinreach and sight of the driver in a driver's seat of the vehicle.

The audio-apparatus main body 22 is comprised of a signal switch, asignal amplifier, and the like to amplify an inputted speech signal andoutput the amplified speech signal to the speaker 13. Theaudio-apparatus main body 22 also functions means for controlling thefollowing function. That is, when the audio-apparatus main body 22 hasnot received a signal indicating that speech recognition is in operationfrom the speech recognition apparatus 10, it determines that the signalreceived from the audio operating unit 21 is not a signal related tospeech recognition and executes a specified operation. On the otherhand, when the audio-apparatus main body 22 has received the signalindicating that speech recognition is in operation from the speechrecognition apparatus 10, it determines that the signal received fromthe audio operating unit 21 is a signal related to speech recognitionand does not execute the specified operation based on the signal. Here,the audio operating unit 21 functions as means for receiving aninstruction based on an operation performed by a user for the speechrecognition in addition to the specified operation and for thenoutputting a signal corresponding to the instruction or the operation bythe user.

The display unit 40 is a color display device. Examples of the displayunit 40 include a liquid crystal display, an organic EL display, and aCRT, of which any may be used appropriately. The display unit 40 canalso display various data items outputted from an onboard navigationapparatus 50, which will be described later. The display unit 40functions as means for reporting in conjunction with the speaker 13.

-Description of Speech Recognition Process (1)-

A description will be given next to a speech recognition process (1)executed by the control unit 11 of the speech recognition system 1 withreference to the flowchart of FIG. 2 and FIGS. 4A and 4B.

The execution of the speech recognition process (1) is started when theuser gives a particular instruction in a state in which a speech inputcan be received when information is inputted to the speech recognitionsystem 1.

First, the control unit 11 remains on standby while it determines that aspeech recognition start switch 80 has not been pressed down (S105: N).When it is determined that the speech recognition start switch 80 hasbeen pressed down (S105: Y), the control unit 11 outputs a signalindicating volume down to a mute level to the audio-apparatus main body22 via the in-vehicle LAN (S110). The control unit 11 also outputs asignal indicating that speech recognition is in operation to the variousECUs via the in-vehicle LAN (S115). The control unit 11 further receivesa speech input as follows. That is, the control unit 11 converts thespeech input received via the microphone 16 to a digital signal by usingthe A/D converter 14 and analyzes the converted digital signal (extractsthe characteristic parameters and the like). The control unit 11 thencompares the analyzed digital signal with the characteristic parametersfor syllables acquired from the HDD 17 via the memory device 15 andselects multiple candidate syllables or candidate words, while givingpriorities thereto (S120). At this time, when only one candidatesyllable or word has been selected (S125: N), the whole process flowreturns to Step S105. When there are multiple selected candidatesyllables or words (S125: Y), the control unit 11 controls the displayunit 40 such that the plurality of candidate syllables or words aredisplayed (S130).

Subsequently, the control unit 11 determines whether or not a signal hasbeen outputted from the audio operating unit 21 via the in-vehicle LAN(S135). When it is determined that the signal has been outputted fromthe audio operating unit 21 via the in-vehicle LAN (S135: Y), thecontrol unit 11 interprets/determines the content of the signal (S165)and controls a target apparatus (S170). In the present embodiment, thetarget apparatus is the audio apparatus 20.

For example, FIGS. 4A and 4B illustrate an example of a selectionprocess. In FIG. 4A, although a speech input was “Akita Prefecture,”“Aichi Prefecture” is listed at the top priority level with “AkitaPrefecture” on the lower level. In FIG. 4B, after the selection process,“Akita Prefecture” is selected from within the plurality of candidatewords and outputted via the speaker 13. In this case, the control unit11 interprets that the signal from the audio operating unit 21 indicatesthe selection of the one of the plurality of candidate words which is onthe lower level and changes the selected candidate word from “AichiPrefecture” (see FIG. 4A) to “Akita Prefecture” (see FIG. 4B).Simultaneously, the selected candidate word “Akita Prefecture” ispronounced via the speaker 13. The whole process flow then returns toStep S135.

On the other hand, when it is determined that the signal has not beenoutputted from the audio operating unit 21 via the in-vehicle LAN (S135:N), the control unit 11 determines whether or not the speech recognitionstart switch 80 has been pressed down (S140). When it is determined thatthe speech recognition start switch 80 has been pressed down (S140: Y),the control unit 11 receives a speech input (S141) and controls thetarget apparatus in accordance with the result of speech recognition(S160). The whole process flow then returns to Step S135.

On the other hand, when it is determined that the speech recognitionstart switch 80 has not been pressed down (S140: N), the control unit 11determines whether or not a sequence of operations associated withspeech recognition have ended (S145). When it is determined that thesequence of operations associated with speech recognition have not ended(S145:N), the whole process flow returns to Step S135. On the otherhand, when it is determined that the sequence of operations associatedwith speech recognition have ended (S145: Y), the control unit 11outputs a signal indicating that speech recognition is not in operationto the various ECUs via the in-vehicle LAN (S150). Then, the controlunit 11 outputs the signal indicating cancellation of volume down to amute level to the audio-apparatus main body 22 via the in-vehicle LAN(S155). The whole process then returns to Step S105.

Effects of First Embodiment

(1) Thus, in the speech recognition system 1 according to the firstembodiment, the audio operating unit 21 of the audio apparatus 20 isused for speech recognition. That is, when it is determined that thespeech recognition start switch 80 has been pressed down (S105: Y), thesignal indicating volume down to a mute level is outputted to theaudio-apparatus main body 22 via the in-vehicle LAN (S110). In addition,the signal indicating that speech recognition is in operation isoutputted to the various ECUs via the in-vehicle LAN (S115) so thatspeech recognition is executed. When it is determined that the signalfrom the audio operating unit 21 has been outputted via the in-vehicleLAN (S135: Y), the content of the signal is interpreted/determined(S165) so that the audio apparatus 20 as the target apparatus iscontrolled (S170). Thus the first embodiment uses the audio operatingunit 21 constructed as the separate part from the audio-apparatus mainbody 22 for the speech recognition system 1. The convenience of thespeech recognition system 1 can be increased without increasing thenumber of operating units.

(2) In addition, in the speech recognition system 1 according to thefirst embodiment, the audio operating unit 21 is disposed in thesteering wheel 60. As a result, the driver is allowed to easily operatethe audio operating unit 21 even during driving and the convenience ofthe speech recognition system 1 can be increased.

Second Embodiment

In the speech recognition system 1 according to the first embodimentdescribed above, the audio operating unit 21 and main body 22 of theaudio apparatus 20 have been constructed as the separate individualparts. By contrast, in a speech recognition system 101 according to thesecond embodiment of the present invention, an audio apparatus 120 is anelectronic apparatus to include an audio operating unit (or an audiooperating panel) 121 and an audio-apparatus main body 122 in a singleassembly.

As shown in FIG. 5, the speech recognition system 101 is mounted on avehicle and is comprised of the speech recognition apparatus.10, theaudio apparatus 120, and the display unit 40. Since the speechrecognition apparatus 10 and the display unit 40 according to the secondembodiment are common to the speech recognition apparatus 10 and thedisplay unit 40 provided in the speech recognition system 1 according tothe first embodiment, the description thereof will be omitted by usingthe same reference numerals as used for the speech recognition system 1according to the first embodiment. The speech recognition apparatus 10,the audio apparatus 120, and the display unit 40 are connected to bemutually communicative via an in-vehicle LAN. To the in-vehicle LANmentioned above, the onboard navigation apparatus 50 and various ECUsnot shown are connected.

-Description of Structure of Audio Equipment 120-

The audio operating unit 121 outputs a signal indicating an increase ora decrease in volume to the audio-apparatus main body 122 based on anoperation by the user.

The audio-apparatus main body 122 is composed of a signal switch, asignal amplifier, and the like to amplify an inputted speech signal andoutput the amplified speech signal to the speaker 13.

The audio-apparatus main body 122 also has the following function. Thatis, when the audio-apparatus main body 122 has not received a signalindicating that speech recognition is in operation, it determines thatthe signal indicating the operation that has been received by the audiooperating unit 121 is not a signal related to speech recognition andexecutes a specified operation based on the signal without transmittingthe signal to the speech recognition apparatus 10. When theaudio-apparatus main body 122 has received the signal indicating thatspeech recognition is in operation, it determines that the signalindicating the operation that has been received by the audio operatingunit 121 is a signal related to speech recognition and transmits thesignal to the speech recognition apparatus 10 without executing thespecified operation based on the signal. It is also possible to allowthe speech recognition apparatus 10 to receive the signal from the audiooperating unit 121 and make a spontaneous determination.

In the present embodiment, the audio apparatus 120 is allowed not to usefor performing the specified operation the signal, which indicates anoperation and has been received by the audio operating unit 121 duringspeech recognition. The audio apparatus 120 further has a function notto disturb the operation of the speech recognition during speechrecognition. In other words, in the audio apparatus 120, a function ofthe specified operation, which may disturb the operation of the speechrecognition, becomes invalidated during the speech recognition.Therefore, the present embodiment uses the audio operating unit 121 ofthe audio apparatus 120 for speech recognition in the speech recognitionsystem 1.

-Description of Speech Recognition Process (2)-

A description will be given next to a speech recognition process (2)executed by the control unit 11 of the speech recognition system 101with reference to the flowchart of FIG. 5.

The execution of the speech recognition process (2) is started when theuser gives a particular instruction in a state in which a speech inputcan be received when information is inputted to the speech recognitionsystem 101.

First, the control unit 11 remains on standby while it determines thatthe speech recognition start switch 80 has not been pressed down (S205:N). When it is determined that the speech recognition start switch 80has been pressed down (S205: Y), the control unit 11 outputs the signalindicating volume down to a mute level to the audio apparatus 120 viathe in-vehicle LAN (S210). The control unit 11 also outputs the signalindicating that speech recognition is in operation to the various ECUsvia the in-vehicle LAN (S215). The control unit 11 further receives aspeech input as follows. That is, the control unit 11 converts thespeech input received via the microphone 16 to a digital signal by usingthe A/D converter 14 and analyzes the digital signal resulting from theconversion (extracts the characteristic parameters and the like). Thecontrol unit 11 then compares the analyzed digital signal with thecharacteristic parameters for syllables acquired from the HDD 17 via thememory device 15 and selects multiple candidate syllables or words,while giving priorities thereto (S220). At this time, when only onecandidate syllable or word has been selected (S225: N), the wholeprocess flow returns to Step S205. When there are multiple selectedcandidate syllables or words (S225: Y), the control unit 11 controls thedisplay unit 40 such that the plurality of candidate syllables or wordsare displayed (S230).

Subsequently, the control unit 11 determines whether or not a signal hasbeen outputted from the audio apparatus 120 via the in-vehicle LAN(S235). When it is determined that the signal has been outputted fromthe audio apparatus 120 via the in-vehicle LAN (S235: Y), the controlunit 11 interprets/determines the content of the signal (S265) andcontrols a target apparatus (S270). In the present embodiment, thetarget apparatus is the audio apparatus 120. The whole process flow thenreturns to Step S235. On the other hand, when it is determined that thesignal has not been outputted from the audio apparatus 120 via thein-vehicle LAN (S235: N), the control unit 11 determines whether or notthe speech recognition start switch 80 has been pressed down (S240).When it is determined that the speech recognition start switch 80 hasbeen pressed down (S240: Y), the control unit 11 receives a speech input(S241) and controls the target apparatus in accordance with the resultof speech recognition (S260). The whole process flow then returns toStep S235.

On the other hand, when it is determined that the speech recognitionstart switch 80 has not been pressed down (S240: N), the control unit 11determines whether or not a sequence of operations associated withspeech recognition have ended (S245). When it is determined that thesequence of operations associated with speech recognition have not ended(S245:N), the whole process flow returns to Step S235. On the otherhand, when it is determined that the sequence of operations associatedwith speech recognition have ended (S245: Y), the control unit 11outputs a signal indicating that the speech recognition is not inoperation to the various ECUs via the in-vehicle LAN (S250). Then, thecontrol unit 11 outputs the signal indicating cancellation of volumedown to a mute level to the audio apparatus 120 via the in-vehicle LAN(S255). The whole process then returns to Step S205.

-Description of Mute Process-

A description will be given next to a mute process executed by the mainbody 122 of the audio apparatus 120 with reference to the flowchart ofFIG. 7.

The mute process is repeatedly executed when the power source of theaudio apparatus 120 is ON.

First, the audio-apparatus main body 122 remains on standby until itdetermines that an indication that speech recognition is in operationhas been received from the sound recognition apparatus 10 (S310: N).When it is determined that the indication that speech recognition is inoperation has been received from the sound recognition apparatus 10(S310: Y), the audio-apparatus main body 122 comes into a state in whichit determines whether or not a signal from the audio operating unit 121is to be transmitted to the speech recognition apparatus 10 (S320). Whenit is determined that the signal from the audio operating unit 121 isnot to be transmitted to the speech recognition apparatus 10 (S320: N),the audio-apparatus main body 122 remains on standby by repeatedlyexecuting Step S320. When it is determined that the signal from theaudio operating unit 121 is to be transmitted to the speech recognitionapparatus 10 (S320: Y), the audio-apparatus main body 122 transmits thesignal to the speech recognition apparatus 10 (S330).

Subsequently, the audio-apparatus main body 122 determines whether ornot an indication that speech recognition is not in operation has beenreceived from the speech recognition apparatus 10 (S340). When it isdetermined that the indication that speech recognition is not inoperation has not been received from the speech recognition apparatus10, the audio-apparatus main body 122 determines that a sequence ofspeech recognition process steps have not ended (S340: N) so that thewhole process flow moves to Step S320. On the other hand, when it isdetermined that the indication that speech recognition is not inoperation has been received from the speech recognition apparatus 10,the audio-apparatus main body 122 determines that the sequence of speechrecognition process steps have ended (S340: Y) so that the whole processflow moves to Step S310.

Effects of Second Embodiment

(1) Thus, in the speech recognition system 101 according to the secondembodiment, the audio operating unit 121 of the audio apparatus 120 isused for speech recognition. That is, when it is determined that thespeech recognition start switch 80 has been pressed down (S205: Y), thesignal indicating volume down to a mute level is outputted to the audioapparatus 120 via the in-vehicle LAN (S210). In addition, the signalindicating that speech recognition is in operation is outputted to thevarious ECUs via the in-vehicle LAN (S215) so that speech recognition isexecuted. When it is determined that the signal from the audio apparatus120 has been outputted via the in-vehicle LAN (S235: Y), the content ofthe signal is interpreted/determined (S265) so that the audio apparatus120 as the target apparatus is controlled (S270). On the other hand,when the audio apparatus 120 determines that the indication that thevolume is to be lowered to a mute level has been received from thespeech recognition apparatus 10 (S310: Y) and that there is an inputfrom the audio operating unit 121 (S320: Y), it transmits the inputtedsignal indicating an operation to the speech recognition apparatus 10(S330).

Thus, by using the audio operating unit 121 of the audio apparatus 120for speech recognition, the convenience of the speech recognition system101 can be increased without increasing the number of operating units.

Other Embodiments

Although the individual embodiments of the present invention have beendescribed thus far, the present invention is not limited to theembodiments described above. The present invention can be embodied inthe following various forms.

(1) Although the audio operating unit 21 is disposed in the steeringwheel 60 in the first embodiment described above, the present inventionis not limited thereto. The audio operating unit 21 may also be disposedat another place so long as it is within sight of a driver duringdriving. For example, the audio operating unit 21 may be disposed on theperiphery of an instrument panel 70 (in FIG. 2). In such a structurealso, the driver is allowed to easily operate the audio operating unit21 even during driving and the convenience of the speech recognitionsystem 1 can be increased.

(2) The audio operating unit 21 may also be disposed at another place solong as it is within reach of the driver. For example, the audiooperating unit 21 may be disposed on the periphery of the instrumentpanel 70. In such a structure also, the driver is allowed to easilyoperate the audio operating unit 21 even during driving and theconvenience of the sound recognition system 1 can be increased.

(3) Although the first embodiment has used the audio operating unit 21of the audio apparatus 20 for speech recognition, the present inventionis not limited thereto. It is also possible to use an operating unit ofan electronic apparatus for speech recognition so long as the electronicapparatus is allowed not to use a signal, which is received from theoperating unit, for performing a specified operation when the speechrecognition apparatus is performing speech recognition. For example, theoperating unit of the electronic apparatus may be a mirror adjustmentswitch, a switch of an air conditioner, or the like. In such a structurealso, the operation of the electronic apparatus remains unaffected evenwhen the operating unit thereof is used for speech recognition and theconvenience of the speech recognition system 1 can be increased.

(4) It is also possible to use an operating unit of an electronicapparatus for speech recognition so long as the function of theelectronic apparatus, which disturbs the speech recognition, isinvalidated when the speech recognition apparatus is performing speechrecognition. For example, the electronic apparatus may be the onboardnavigation apparatus 50 or the like. In such a structure also, theoperation of the electronic apparatus remains unaffected even when theoperating unit thereof is used for speech recognition and theconvenience of the speech recognition system 1 can be increased.

(5) Alternatively, the speech recognition apparatus 10 according to eachof the embodiments described above may also be implemented by using thestructure of the onboard navigation apparatus 50. Such a structure alsoachieves the same operations and effects achieved by the embodimentsdescribed above.

Each or any combination of processes, steps, or means explained in theabove can be achieved as a software unit (e.g., subroutine) and/or ahardware unit (e.g., circuit or integrated circuit), including or notincluding a function of a related device; furthermore, the hardware unitcan be constructed inside of a microcomputer.

Furthermore, the software unit or any combinations of multiple softwareunits can be included in a software program, which can be contained in acomputer-readable storage media or can be downloaded and installed in acomputer via a communications network.

It will be obvious to those skilled in the art that various changes maybe made in the above-described embodiments of the present invention.However, the scope of the present invention should be determined by thefollowing claims.

1. A speech recognition system in a vehicle, the system comprising: a speech recognition apparatus for performing speech recognition; an electronic apparatus for performing at least a specified operation; and a communication network via which the speech recognition apparatus and the electronic apparatus are communicative, wherein the speech recognition apparatus includes: a notifying unit for transmitting, when performing speech recognition, an operating signal indicating that the speech recognition is in operation to the electronic apparatus; a speech recognizing unit for performing speech recognition to specify a candidate for a speech inputted by a user; a reporting unit for reporting the specified candidate so as to require the user to indicate an instruction; and a first control unit for executing, when receiving an instruction signal indicating an operation performed by the user, a subsequent process based on the received instruction signal, wherein the electronic apparatus includes: a receiving unit for receiving an operation performed by the user and generating a corresponding instruction signal; and a second control unit for, when not receiving the operating signal, determining that the instruction signal is not related to speech recognition and executing the specified operation based on the instruction signal, and when receiving the operating signal, determining that the instruction signal is related to speech recognition and transmitting, without executing the specified operation based on the instruction signal, the instruction signal to the speech recognition apparatus, and wherein the speech recognition apparatus then executes the subsequent process based on the instruction signal transmitted from the electronic apparatus.
 2. The speech recognition system of claim 1, wherein the receiving unit included in the electronic apparatus is constructed as an independent portion, which is separate from a main body of the electronic apparatus, and the speech recognition apparatus, the receiving unit of the electronic apparatus, and the main body of the electronic apparatus are mutually communicative via the communication network.
 3. The speech recognition system of claim 1, wherein the receiving unit is disposed within reach of the user in a driver's seat of the vehicle.
 4. The speech recognition system of claim 1, wherein the receiving unit is disposed within sight of the user in a driver's seat of the vehicle.
 5. The speech recognition system of claim 1, wherein the receiving unit is disposed in a steering wheel of the vehicle.
 6. The speech recognition system of claim 1, wherein the receiving unit is disposed on a periphery of an instrument panel of the vehicle.
 7. The speech recognition system of claim 1, wherein the electronic apparatus is allowed not to use the instruction signal for performing the specified operation when the operating signal is received.
 8. The speech recognition system of claim 1, wherein the electronic apparatus has a function not to disturb speech recognition when the operating signal is received.
 9. The speech recognition system of claim 1, wherein the electronic apparatus includes an audio apparatus, and an audio volume of the audio apparatus is decreased to a mute level when the operating signal is received.
 10. The speech recognition system of claim 1, wherein when the candidate specified by the speech recognizing unit includes a plurality of items, the receiving unit is used for the user to select one of the plurality items.
 11. The speech recognition system of claim 1, wherein when the candidate specified by the speech recognizing unit includes a plurality of words, the reporting unit reports the specified candidate as the plurality of words to the user and the user is required to select to one of the plurality of words.
 12. The speech recognition system of claim 1, wherein the speech recognition apparatus further includes a speech receiving unit for receiving a speech inputted by the user.
 13. The speech recognition system of claim 12, wherein the notifying unit transmits the operating signal indicating that the speech recognition is in operation to the electronic apparatus when the speech receiving unit receives a speech inputted by the user.
 14. The speech recognition system of claim 1, wherein the speech recognition apparatus further includes a speech recognition start switch for the user to indicate a start of speech recognition, and the notifying unit transmits the operating signal indicating that the speech recognition is in operation to the electronic apparatus when the user indicates a start of speech recognition via the speech recognition start switch.
 15. A speech recognition system in a vehicle, the system comprising: a speech recognition apparatus for performing speech recognition; an electronic apparatus for performing at least a specified operation; an operating panel for distributing an instruction signal corresponding to an operation performed by a user; and a communication network via which the speech recognition apparatus, the operating panel, and the electronic apparatus are mutually communicative, wherein the speech recognition apparatus includes: a first receiving unit for receiving the instruction signal from the operating panel; a notifying unit for transmitting, when performing speech recognition, an operating signal indicating that the speech recognition is in operation to the electronic apparatus; a speech recognizing unit for performing speech recognition to output a candidate for a speech inputted by a user; a reporting unit for reporting the candidate so as to require the user to indicate an instruction; and a first control unit for executing, when receiving an instruction signal specifying an item from the candidate by the instruction performed by the user via the operating panel, a subsequent process based on the received instruction signal from the operating panel, wherein the electronic apparatus includes: a second receiving unit for receiving the instruction signal from the operating panel performed by the user; and a second control unit for, when not receiving the operating signal, determining that the instruction signal is not related to speech recognition and executing the specified operation based on the instruction signal, and when receiving the operating signal, determining that the instruction signal is related to speech recognition and not executing the specified operation based on the instruction signal, and wherein the speech recognition apparatus then executes the subsequent process based on the instruction signal transmitted from the operating panel.
 16. The speech recognition system of claim 15, wherein the operating panel is included in the electronic apparatus and the second control unit included in the electronic apparatus transmits the instruction signal to the speech recognition apparatus.
 17. The speech recognition system of claim 15, wherein the operating panel is disposed within reach of the user in a driver's seat of the vehicle.
 18. The speech recognition system of claim 15, wherein the operating panel is disposed within sight of the user in a driver's seat of the vehicle.
 19. The speech recognition system of claim 15, wherein the operating panel is disposed in a steering wheel of the vehicle.
 20. The speech recognition system of claim 15, wherein the operating panel is disposed on a periphery of an instrument panel of the vehicle.
 21. The speech recognition system of claim 15, wherein the electronic apparatus is allowed not to use the instruction signal for performing the specified operation when the operating signal is received.
 22. The speech recognition system of claim 15, wherein the electronic apparatus has a function not to disturb speech recognition when the operating signal is received.
 23. The speech recognition system of claim 15, wherein the electronic apparatus includes an audio apparatus, and an audio volume of the audio apparatus is decreased to a mute level or power of the audio apparatus is turned off when the operating signal is received.
 24. The speech recognition system of claim 15, wherein when the candidate outputted by the speech recognizing unit includes a plurality of words as a result of an execution of speech command, the reporting unit reports the specified candidate as the plurality of words to the user and the user is required to select one of the plurality of words and the operating panel is used for the user to select one of the plurality words.
 25. The speech recognition system of claim 15, wherein when the candidate output by the speech recognizing unit includes a plurality of words as a result of speech analysis, the reporting unit reports the specified candidate as the plurality of words to the user and the user is required to select one of the plurality of words.
 26. The speech recognition system of claim 15, wherein the speech recognition apparatus further includes a speech receiving unit for receiving a speech inputted by the user.
 27. The speech recognition system of claim 26, wherein the notifying unit transmits the operating signal indicating that the speech recognition is in operation to the electronic apparatus when the speech receiving unit receives a speech inputted by the user.
 28. The speech recognition system of claim 15, wherein the speech recognition apparatus further includes a speech recognition start switch for the user to indicate a start of speech recognition, and the notifying unit transmits the operating signal indicating that the speech recognition is in operation to the electronic apparatus when the user indicates a start of speech recognition via the speech recognition start switch. 